Get rid of her using your magic

She's close to you, and your fingers blaze with deadly energy when you unleash the spell, a vampiric touch to drain her life. But her ring pulses with holy energy and your magic is siphoned into it.

"Oh, darling" she laughs "Undead magic to attack a priest?"
She casts a spell and you see a flash of light... then, nothing.

You wake up completely nude in a dungeon, with an iron collar sealing your magic. You can't speak... your tongue is numb.

She shouts "Train her, if she's good enough, we will keep her as a servant" and she leaves the room.
This can't be true! You have to do something, but you are powerless, and you notice two other girls around you with whips.

You can obey and try to escape later, or you can try to use all your strength and escape now.